\documentclass{article}
\usepackage{amssymb,amsmath,amscd,concmath}
\pagestyle{empty}
\begin{document}
\begin{equation*} \textbf{x}_{k} = \textbf{F} \textbf{x}_{k-1} + \textbf{G w}_{k}\end{equation*}
\end{document}
